The present invention comprises a new and distinct cultivar of a birch tree, botanically known as Betula papyrifera, and is hereto referred to by the cultivar name xe2x80x98Cencixe2x80x99.
xe2x80x98Cencixe2x80x99 was discovered by the inventor in a group Betula papyrifera in a provenance test plot planted in Wooster, Ohio in 1986. xe2x80x98Cencixe2x80x99 was originated from the open pollinated cross in a birch selection/breeding program on Evergreen Nursery Company property. The female parent was Betula papyrifera. The male parent is unknown. xe2x80x98Cencixe2x80x99 was first noticed with a tight, oval, compact growth habit, white large, shaggy, persisting exfoliating bar and a high resistance to the Bronze Birch Borer. The cultivar has been asexually reproduced in Sturgeon Bay, Wis. and Wooster, Ohio. Presently, reproduction is accomplished by micropropagation or tissue culture propagation by the inventor from the initial selection in Sturgeon Bay, Wis. Horticultural examination of selected units has demonstrated that the combination of characteristics has herein disclosed for xe2x80x98Cencixe2x80x99 are firmly fixed and retained through its successive generations of asexual reproduction. xe2x80x98Cencixe2x80x99 has been observed in Sturgeon Bay, Wis., and Wooster, Ohio, since 1986 and characteristics have been stably maintained. The cultivar reproduced true to type. The new cultivar has not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment such as temperature, day length and light intensity, without a change in the genotype of the new cultivar. The following observations, measurements and comparisons describe the plants grown in Sturgeon Bay, Wis. under natural field conditions which approximate those generally used in commercial growing operations.
The following traits have been repeatedly observed and are determined to be basic characteristics of xe2x80x98Cencixe2x80x99 which in combination distinguish this birch tree as a new and distinct cultivar:
1. Distinctive tight, oval, compact growth habit with a good central leader and branching angles about 35-40xc2x0.
2. Bark color changes as the tree matures; from brown turning to white.
3. White, large, shaggy, persisting exfoliating bark when mature.
4. High resistance to the Bronze Birch Borer.
5. Slow to moderate growth rate.
The new cultivar can be compared to the non patented Betula papyrifera for the foregoing characteristics differ from the nonpatented variety in that the nonparented variety has variable resistance to the Bronze Birch Borer, has a loose oval growth habit and the bark exfoliates in smaller pieces.